1. Field of the Invention
The present invention relates to a weather strip configured so that an insert is embedded in a trim portion.
2. Related Art
Generally, a weather strip having a trim portion is provided on a flange formed along the peripheral part of a door opening of a vehicle, such as an automobile. The weather strip has a trim portion, which has a holding lip held by being fit into the flange formed along the peripheral part of the door opening, and also has a hollow seal portion provided to protrude from the trim portion. The trim portion has a connecting portion, which connects a vehicle interior side wall, a vehicle exterior side wall, and both side walls, and is substantially-U-shaped in cross section.
Also, a metal insert is embedded in the trim portion. As illustrated in FIG. 8, an insert 90 has a plurality of strip-like piece portions 91 disposed substantially parallel to one another and bond portions 92 (e.g., a center bond portion placed in the connecting portion) that connect the piece portions 91 to one another. Incidentally, FIG. 8 illustrates the insert 90 that is in a state before each of the piece portions 91 is subjected to bending-work and is formed into a substantially U-shape.
When a weather strip is mounted on the flange, the trim portion is fit thereinto. A mounted state, in which the weather strip is mounted thereon, is maintained basically by an elastic force of the holding lip portion or a bonding force of the insert. Additionally, when a door is closed, an edge portion of the door abuts against the seal portion. Thus, the seal portion is crush-deformed to seal between the door and a body of the vehicle.
In recent years, there has been an increasing demand for lightening the weather strip. Because the ratio in weight of the metal insert to the weather strip is high, the weight of the insert is reduced to thereby lighten the weather strip. A technique of lightening the insert is to form the center bond portion to be thin, as compared with the piece portions (see, for example, JP-A-11-48879).
However, according to the above technique, only the center bond portion is formed to be thin. Thus, the weather strip cannot always sufficiently be lightened. On the other hand, when even the piece portions are formed to be thin to fit to the center bond portion, a desired strength (or shape holding performance) cannot be assured. Consequently, the bonding force is insufficient.